Relationship Goals: 5 ways Nick Offerman and Megan Mullally are keeping it real

Nick Offerman and Megan Mullally have been together for 18 years. That’s a lifetime by Hollywood standards.

Naturally fans of the two mega-stars want to know more about their staying power.

Offerman, who is starring in the feel-good drama, “Hearts Beat Loud,” stopped by the ABC News studios to talk about his new film and shared how he and Mullally first met.

1. Their love took time

It wasn’t quite love at first sight for Offerman and Mullally. In fact, Offerman thought Mullally was out of his league. But he took the time to get to know her and his patience paid off.

“Deep down, I think there was a sensibility of I’m just a stage carpenter donkey. I don’t think I could ever turn this lady’s head,” Offerman said in a recent appearance on “Popcorn with Peter Travers.” “We began to notice each other and say, ‘Oh I think we’re going to be great friends.’ And as she put it, a couple of weeks in, she thought, ‘Wait a minute, is this guy cute?' That was just the crack I needed in the dike and now it’s a running river.”

2. Bedroom rules still apply

Offerman says he once tested the limits of their relationship when he shaved his head in a clown-like fashion for a role in a play.

“Megan is incredibly generous,” Offerman said. “There was one time I was doing a play and I shaved off the top of my head and I had sort of Larry Fine crazy, male-patterned baldness with a huge beard. And during that period, she wouldn’t let me into our bed, which was understandable. I hit the couch for a few nights until one night I had an inspiration. I knocked on the bedroom door and I had a stocking cap on.”

3. Nothing is off limits

Offerman said their fan base started to express a fascination with their relationship. So the couple decided to go on tour together last year, sharing an honest look at their marriage. They called the tour the “Summer of 69: No Apostrophe.”

“We said lets come up with a show and let’s make fun of our marriage that people make such a big deal out of. It's not particularly factual. It’s more written to take the piss out of the reality of our relationship,” Offerman said.

4. They continue to do their own things

“We had been touring separately. Me as a humorist and she with her band, Nancy and Beth,” Offerman, 47, told Travers. “And it’s a lot of fun. We love doing it. But we miss each other.”

5. Greatest Love Story Ever Told

Offerman and Mullally plan to take their relationship transparency one step further. The two have been spending time writing together.

“We have a book coming out this fall called 'The Greatest Love Story Ever Told,'” Offerman said. “What you find within, these are real people, hopefully with a good sense of humor and a little bit of pith that we can all relate to. We present our marriage for the world in the hopes that people will glean some understanding or some sort of advice from it. Meghan’s reactions to me in the book still make me laugh out loud.”

Offerman also talked about his new role in “Hearts Beat Loud,” where he plays a single dad running a failing vinyl store in Brooklyn. Kiersey Clemons plays Offerman's daughter.

“They love playing music together,” Offerman said. “And it’s my character’s dream to be in a successful band. And things are just starting to pop for he and his daughter when she has to leave for college.”

He added, “The sort of theme of the movie is when you experience loss in your life, there’s a sensibility of can we move forward in our lives? Can we still have beauty? Can you hang on to your dream while leaving the past behind and moving forward? So it’s quite evocative and moving. It’s well written. I didn’t have to dig very deep because the scenes are well-crafted.”

"Hearts Beat Loud" is in theaters everywhere.

Be sure to watch the full interview with Peter Travers and Nick Offerman in the video above.